Mimi (pumilum x Doris Aurea) is in full bloom now. It is a robust plant yielding multiple flower spikes; whereas, I'm still struggling to get the proper culture conditions so that Cym. pumilum (syn. floribundum) will flower for me.
According to RHS, 65 registered grexes have Mimi as the pod parent, and 5 as the pollen parent. I don't know the ploidy of this clone, and it appears that some Mimi clones can breed as if tetraploid. When visiting a colleague's greenhouse earlier this week, I was shown another Mimi clone which was half the size of 'Mary Bea', flowers and all, which made me think that his clone may be the diploid form. Regardless, given the intense raspberry jam colors, I can see why many have used this grex for additional breeding.
However, a curious thing happened during flower development. While most inflorescences yielded normal-looking flowers, one spike gave rise to flowers in which the posterior (lower) half of the lateral sepals partially transformed into the lip! Not all flowers on this spike show the transformation, and the degree of transformation varies between flowers.
Note the transformation to callus ridge.
From my previous profession as a research scientist, such homeotic transformations (the transformation of one body part into another body part) immediately indicate to me that the interactions between at least two transcription factors that specify the different flower parts are impaired. However, I studied animals, not plants, so I need to browse the plant literature. I expect the plant developmental biologists already have a working model to explain this phenomenon.
3 years ago